Electrical insulator.



No. 689,218'. Patented Dec. I7, IQUI. A. F. PARKS.

ELECTRICAL INSULATOR.

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UNITED STATES PATENT o ALBERT' F. PARKS, OF BROOKLYN, NEW YORK, ASSIGNOR TO LEWIS B.

STAILLWELL, OF NEW YORK, N. Y.

ELECTRICAL iisisuLATon.y

SPECIFICATION forming part of Letters Batent No. 689,218, dated December 1'?, 1 901.

' Application filed April 8,1901. Serial No. 54,812. (No model.)

To all whom it may concer-71,:

Be it known thatKLAALBERr F. PARKS, 'av citizen of the United States, and a resident of Brooklyn, in the countyof `Kings and State of New York, have in vented certain new and useful Improvements in Electrical Insulators, of which the following is a specification.

My invention relates to the class of devices employed for supporting and insulating electric conductors, particularly those carried in the air and employed for the transmission of electric energy in largequantities.

In electric transmission systems Where it is desired to transmit large amounts of power over long distances the conductors are called upon to convey currents of relatively high voltages and are often necessarily large and heavy. For the purpose of meeting the electrical strains due to the high potential it is customary to increase the size, quality, and effective surface of the insulators; but often the supports upon which the insulators have been carried have been of relatively small size and therefore of insufficient mechanical strength to support the weight of the conductors and resist the various mechanical strains l to which they are subjected by reason of weight and Wind-pressure. In some instances the pins have been made of metal; but this is objectionable on account of the difficulty of securing a sufficiently accurate tit between the threads of the pin and those of the insulator, both being of rigid and unyielding material and having different coefficients of eX- pansion. Usually also the metal pins have been of inadequate mechanical strength to resist Wind-pressure and the repeated stra-ins due to swinging weight of the conductors. In some instances metalpinsy surrounded by a threaded Wooden sleeve have been used; but these are generally of insufficient mechanical strength and are objectionable for the reason that the threads of the wood sleeve are easily stripped by the mechanical strains transmitted from insulator to pin. Another serious diiculty in the case of these pins and also in the case of pins consisting entirely of wood arises from the liability of the wood to be burned by'excessive leakage of current.

The general plan of the invention is to construct an insulator of sufficient size and strength and to support this upon a threaded pin, usually of wood and therefore capable of adapting itself to any irregularities of the threads Aof the insulator, this pin being in turn supported in a metallic socket adapted to be secured to the cross-armor other support. Suitable means are provided for preventing the insulator from being screwed too far onto the pin and for distributing the local strains.

In the accompanying drawings, Figure l illustrates one form of the insulator, and Fig. 2 a modification.

Referring to the figures, l represents a pin, which may be of wood or other suitable material. This is shown in Fig. l as being provided with reversed screw ends 2 3, between which is a spherical enlargement 4. The feature of the reversed thread possesses value from the fact that by its use yit becomes possible to remove the pin from the insulator and containing-socket at one operation, a feature of importance when the insulator may be placed, for instance, in a position difficult of access. The insulator, which may be of porcelain or glass or any other suitable material, is represented at 5 and may be of any suitable shape or configuration. It is screwed onto the threaded end 2 of the pin until it strikesas shown in Fig. 1, and this may be construct' ed with a petticoat 10, similar to the insulator itself. It is here shown as extending upward into the hollow portion of the insulator 5.

In Fig. 2 a modiication is shown, in which the metal socket 6 is somewhat enlarged at the base to afford a wider bearing-surface. The insulating-sleeve 9 is here shown as covering the socket and extending into the hol.-

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low portion of the insulator 5, the latter being of slightly-different configuration than that shown in Fig. 1. The bolt 8 for securing the insulating device to the insulatorarm may be made removable, as shown in this figure, and it may extend through the insulator-arm and 4be fastened by a nut and washer 11 in any well-known manner. An insulator-support constructed in the manner above described possesses great mechanical strength. It allows ot' a more economical size of crossearm, no large hole being required through it to receive a large wooden pin. Moreover, the insulator may be placed high above the cross-arm by giving any required length to the socket-pin, thus lessening the liability of contact with snow which may accumulate. Moreover, it provides an incombustible support and a pin which may be quickly and easily removed.

Iclaim as my invention* l. The combination with a cross-arm orsupport, of a metallic socket rigidly secured thereto, a pin of softer material secured within said metallic socket, a seat for the insulator upon said pin and means for securing the insulator to said pin and against said seat.

2. The combination with an insulator of the character described,of a support thereforconsisting of a threaded piu of wood or other soft material receiving the insulator upon one end, an enlargementupon the pin against which a portion of the insulatorabuts, and a metallic socket receiving the other end of the pin, substantially as described.

. The combination of a metallic socket, a

threaded wooden pin screwed therein having a reverse thread upon the remaining end,and an insulator screwed to the latter end.

4. A support for receiving a line-wire insulator, consisting ot' a wooden pin having reversed screw-threads upon its respective ends, and an intermediate enlargement.

5. The combination with an insulator for line-wires, of a metallic socket, a wooden pin having reversed screw-threads upon its respective ends,r one end being screwed into the socket and the remaining end into the insulator, thereby rigidly securing the pin to the insulator and the socket, and means for rig-l idly securing the socket to a cross-'arm substantially as described.

6. The combination of an insulator, a pin of yielding material carrying the same, a metallic socket receiving the pin, means for rigidly securing the same to a support, and a sleeve of insulating material surrounding the socket.

7. The combination of an insulator having a downwardly-extending flange, a metallic socket and an extension of said socket of softer material receiving the insulator, anda sleeve of insulating material surrounding the metallic socket and extending within the flange of the insulator.

Signed at New York, in the county of New York and State of New York, this 6th day of April, A. D. 1901.

ALBERT F. PARKS.

Witnesses:

WM. H. CAPEL, GEORGE H. STOCKBRIDGE. 

